Question

soil amendment is ----​

Answer 1

Explanation:

Soil amendments are the practices used to improve mine soil quality in terms of its structure and biochemical function. The adverse soil conditions on post-mining land has a negative impact on the physical and biochemical properties of the soil. To offset the impact of mining on soil, a number of soil amendments such as biochar, fly ash, and compost have been used. There are two basic types of soil amendments have been used to improve soil fertility and stabilize site conditions:

1.

Organic amendments: It is the composition of organic moieties derived from biomass and/or living beings. It generally includes compost, wood chips, biochar, animal manure, straw, husk, geotextile, and sewage manure. These substances are extremely rich in organic matter and macro- and microelements that increase the fertility of soils by ameliorating microclimatic conditions and may also provide substrates for microbial growth. The application of mulch on the dump surface had a significant influence on the rhizosphere temperature and moisture content. A significant reduction in the rhizosphere temperature can be observed under mulch cover, while it was found to be higher in the unreclaimed dump. For example, Wang et al. (2017) studied the effect of mulches and legumes for the restoration of urban abandoned land and reported a decrease in temperature from 6% to 18%.

2.

Inorganic or mineral amendments: These amendments are generally contained minerals associated with soil fertility. Gypsum is commonly used to decrease soil pH by bonding high sodium salts and lime or limestone to decrease the soil pH. Coal combustion byproducts, like fly ash, have received much attention as soil amendments but may contain high amounts of trace elements. It has been observed, that the addition of soil amendments (organic and inorganic) has great potential for increasing soil pH (3.2–7), reducing the solubility of trace metals by more than 80%, and stabilizing the soil (Pardo et al., 2017). The combination of composted sewage sludge and steel mill slag was also used as a potential amendment for afforestation in Brazil that resulted in the increase of soil fertility and plant growth (Guerrini et al., 2017).

Superabsorbent polymers (SAPs) have the capability of absorbing water and retaining it for a long time. They are made up of lightly cross-linked hydrophilic polymers that can absorb a large amount of water and stored it in a readily available form to plants (Maiti, 2012). They also act as food for microbes and soil conditioner, as well as reducing soil erosion and agricultural runoff and they increase fertilizer use efficiency. They can be mixed with the soil during plantation and can also be used in hydro-mulching. The use of various SAPs can increase moisture by 6.2%–32.8%, while reducing soil bulk density by 5.5%–9.4% compared to native soils (Bai et al., 2010).

Boron Toxicity and Tolerance in Plants

Maria Polsia Princi, ... Maria Rosa Abenavoli, in Plant Metal Interaction, 2016

4.1 Early Considerations

Soil amendment such as leaching B with water and application of organic compounds to inactivate or immobilize B in soil has been considered the main approach to solve B toxicity issue for many years. Nowadays, it appears not feasible on a large scale in B-toxic areas because of economic and practical aspects. On the contrary, the most realistic and effective method to increase crop yields in B-rich soils could be the selection of B excess–tolerant genotypes (Nable et al., 1997). Genetic variation for B excess tolerance has been assessed in many crop species since the 1980s until now (Schnurbusch et al., 2010b; Bogacki et al., 2013). Therefore, tolerant varieties can be rather easily bred, offering a most hopeful approach to minimizing decreases in crop yield in areas with high B concentrations in the soil.

Strategies for Soil Protection and Remediation

David Fangueiro, ... Amarilis de Varennes, in Soil Pollution, 2018